Optical coding system using rotatable light sources and code elements

ABSTRACT

This invention has to do with an identification system and, more particularly, to an optical coding system for use in conveyors and the like for identifying articles for subsequent treatment. Two code elements are rotatable to predetermined angular positions on a signal device which moves past a scanning station with two rotatable light sources.

United States Patent [56] Reierences Cited UNITED STATES PATENTS 3,106,706 10/1963 Kolanowski et al...........

Francis P. Dunigan Holden, Mass. 835,334

[72] Inventor 3,180,996 4/1965 Goodetalnmmm 3,365,580 1/1968 Cannella 3,444,385 5/1969 Paglee........,.. .....r.....

Primary Examiner-Walter Stolwein Att0rneyNorman S. Blodgett [21] App]. No.

[22] Filed June 23, 1969 [45] Patented Oct. 5, 1971 [7 3] Assignee MEKontrol, Inc.

Northboro, Mass.

ABSTRACT: This invention has to do with an identification system and, more particularly, to an optical coding system for use in conveyors and the like for identifying articles for subsequent treatment. Two code elements are rotatable to predetermined angular positions on a signal device which 76 1 20W 2/ l9 0 5 20 K 3. 2 2 0 5 2 236, 219 D, 219 DC, 219 DD, 223 moves past a scanning station with two rotatable light sources.

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OPTICAL CODING SYSTEM USING ROTATABLE LIGHT SOURCES AND CODE ELEMENTS BACKGROUND OF THE INVENTION In the control of articles moving along on conveyors, it is common practice to control the fiow of articles in a network by the use of an identification system located at each junction. An example of such an identification system is the retroreflective pattern coding system shown and described in the patent of Edelman US. Pat. No. 3,144,926. Under certain conditions, however, the identification systems of the prior art have not been entirely adequate. Some of them have have been too expensive and complicated, thus requiring costly maintenance procedures using high-cost labor. Other identification systems of the prior art have been too delicate for use in the rugged conditions often associated with conveying systems; when such systems break down, the entire conveying system must be shut down, thus affecting the operation of the entire factory or warehouse in which the conveyor is located. Such a shutdown of a large capital investment is, of course, unbearable, so that such a possibility has limited, to a certain extent, the application of automatic switching equipment of this type to automatic warehousing and the like. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.

It is, therefore, an outstanding object of the invention to provide an identification system which is simple in construction, rugged, and dependable.

Another object of this invention is the provision of an identification system for conveying networks and the like which uses simple mechanical-electrical components.

A further object of the present invention is the provision of an identification system of the optical pattern-coded type wherein the patterns can be quickly and easily changed.

It is another object of the instant invention to provide an identification system in which a large number of pattern codes can be set with apparatus occupying very little space.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

SUMMARY OF THE INVENTION In general, the present invention consists of an identification system having a scanning station with at least two light sources, each located at a predetermined angular position on a circle, the circles lying laterally of one another. A signal device is adapted to move past the scanning station and has at least two code elements, each located at a predetermined angular position on a circle, the circles being of the same size and relative location as to the circles on the scanning station. Means is operative, when the light sources on the scanning station and the code elements on the signal device occupy the same angular positions on corresponding circles, to perform a function related to identification of the signal device.

More specifically, each code element is mounted on a rotary member which is mounted on a flat face of the signal device for rotation about an axis passing through the center of the circle at a right angle to the face and the means for returning the light beam is a cable of optical fibers.

BRIEF DESCRIPTION OF THE DRAWINGS The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated by the accompanying drawings, in which:

FIG. 1 is a perspective view of an identification system embodying the principles of the present invention incorporated into a conveying system,

FIG. 2 is a perspective view of a scanning station,

FIG. 3 is a perspective view of a signal device, and

FIG. 4 is a horizontal sectional view of portions of the scanning device and signal device.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring first to FIG. 1, wherein are'best shown the general features of the invention, the identification system, indicated generally by the reference numeral 10, is shown in use with a conveyor 11. The movable element of the conveyor is shown as consisting of a cable 12 from which hangs a carrierl3. In the illustration, the carrier 13 is in the act of passing a fixed station 14 which, presumably, immediately precedes a junction in the conveyor, so that it is necessary to obtain from the carrier 13 information as to its identity, so that 'theproper signal can be sent out to cause the carrier to go to one branch or the other of the junction. Mounted on the fixed station v14 is a scanning station 15, while mounted onthe carrier '13 is a signal device 16.

In FIG. 2, it can be seen that the scanning station l5'has a generally boxlike configuration with a flat vertical face 17. One side of this face is provided with a light source 18 mounted on one end of an arm 19 which is mounted at its other end on the station for rotation about a pivotal shaft 21 whose axis extends at a right angle to the face 17. The position of the light source 18 can be selected from a plurality of an gular positions spaced about a circle 22 of which the axis of the shaft 21 is the center. A similar light source 23 is mounted at one end of a rotatable arm 24 which is rotated about a pivotal shaft 25 whose axis is the center of another circle 26. The two circles have the same diameter and the arms 19 and .24 have the same length. Both circles 22 and 26 are divided into the same number of angular increments for the setting of the light sources 18 and 23.

In FIG. 3, it can be seen that the signal device 16 has a generally boxlike configuration with a vertical flat face 27. Mounted on the face are two rotary members of dials 28 and 29 having, respectively, at their peripheries code elements 31 and 32. When the dial 28 is rotated, the code element 31 passes from one to another of a plurality of angular stations about the axis of the dial arranged about an imaginary circle, while the code element 32 passes over a similar circle whose center is the center of rotation of the dial 29. Thetwo circles are located in side-by-side relationship on the face 27 and have the same sizes and relative positions as the corresponding circles on the scanning station 15. The center of the dial 28 is provided with a hub 33 whose outer surface is serrated to provide for gripping and for manual rotation of the dial. Centrally of the hub is provided an opening 34 carrying a lens 35. A similar hub 36 extends from the center of the dial 29 and is provided with an opening 37 carrying a lens 38. The circles on the scanning station 15 and the signal device 16 are both provided with suitable indicia to give definite angular positions to which the elements can be set.

Fig. 4 is a vertical sectional view of the scanning station 15 and the signal device as they appear when they are passing one another. The manner in which the arm '19 is mounted on the pivotal shaft 21 is clearly shown, and it can be seen that the arm is provided with a protuberance 39 which engages a dimple 41 formed on the face 17 to lock the light source 18 in an angular position of adjustment. Since the face 27 of the signal device 16 is directed toward the face 17 of the scanning station 15, the light source 18 is directed toward the dial 29 of the signal device. This dial is mounted on a shaft42 for rotation about its axis, and the axis of the shaft 42 during the reading operation shown coincides with the axis of the shaft 21 of the scanning station. When the light source 18 is set for the same angular position in its circle that the code element 32 is on its circle, the light beam passes on a path 43 from the light source 18 to the code element 32. Now, the code element 32 is an opening in the dial 29 and is connected on the interior to one end of a cable 44 of optical fibers, the other end of which resides in the opening 37 behind the lens 38. From the lens 38 the light passes along the common axis of the shaft 42 to a bore 45 in the axis shaft 21. At the base of this bore is mounted a photocell 46 which receives the light and sends out a suitable signal on its electrical leads. These electrical leads are connected in the well-known manner to the control elements of the conveyor 11 to select a route for the carrier 13.

In the operation of the apparatus, the cable 12 will be carrying the carrier 13 through the conveyor 11. Eventually, the carrier with its signal device 16 will arrive at the fixed station 14. The scanning station continually projects a beam of light from the light sources 18 and 23 which have been preset in a coding pattern. As the carrier 13 and the signal device 16 pass the scanning station 15, if the code elements 31 and 32 of the signal device are set in the same angular relationships on their circles as the light sources 18 and 23 are on their circles, there will be simultaneous energization of the photocell 46 associated with the light source 18 and a similar photocell associated with the light source 23. Simultaneous energization of these photocells will set in motion the controls for the diverting of the carrier 13. In most cases, the conveyor 11 will consist of a main path through which the carriers will flow as well as branch paths to which they can be diverted from time to time. It will be understood, of course, that, although the description is related to a conveyor system, nevertheless, the principles of the present invention can be applied to any situation where articles move through a network and junction decisions must be made from time to time.

it is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

The invention having been thus described, what is claimed as new and desired to secure by Letters Patent is:

1. An identification system, comprising a. a scanning station consisting of at least two light sources,

each located at a predetermined angular position on a respective circle, the circles lying laterally of one another, each light source being mounted on an arm which is pivotally mounted on a flat face of the scanning station for rotation about an axis passing through the center of the circle at a right angle to the face,

b. a signal device adapted to move past the scanning station and consisting of at least two code elements, each located at a predetermined angular position on a respective circle, the circles being of the same size and relative location as the circles on the scanning station, and

c means at the centers ofthe scanning station circles operative, when the light sources on the scanning station and the code elements on the signal device occupy the same angular positions on corresponding circles, to perform a function related to identification of the signal device.

2. An identification station as recited in claim 1, wherein the scanning station is provided with a lens system and said means includes a photocell located on the center of the respective circle.

3. An identification station as recited in claim 1, wherein each code element includes a means for returning the light beam which falls on it originating in the light source.

4. An identification system as recited in claim 1, wherein each code element is associated with a light-directing system which reverses the beam that falls on the code element and projects it along an axis passing through the center of the circle at a right angle to the plane thereof.

5. An identification system as recited in claim 4, wherein each code element is mounted on a rotary element which is mounted on a flat face of the signal device for rotation about an axis passing through the center of the circle at a right angle to the face.

6. An identification system as recited in claim 3, wherein the means for returning the light beam is a cable of optical fibers.

7. An identification system as recited in claim 1, wherein the signal device moves with an article attached to a movable portion of a conveyor system, the scanning station is mounted on a fixed portion of the conveyor system, and the said means acts to switch the article when there is pattern identity between the code elements on the signal device and the light sources on the scanning station. 

1. An identification system, comprising a. a scanning station consisting of at least two light sources, each located at a predetermined angular position on a respective circle, the circles lying laterally of one another, each light source being mounted on an arm which is pivotally mounted on a flat face of the scanning station for rotation about an axis passing through the center of the circle at a right angle to the face, b. a signal device adapted to move past the scanning station and consisting of at least two code elements, each located at a predetermined angular position on a respective circle, the circles being of the same size and relative location as the circles on the scanning station, and c. means at the centers of the scanning station circles operative, when the light sources on the scanning station and the code elements on the signal device occupy the same angular positions on corresponding circles, to perform a function related to identification of the signal device.
 2. An identification station as recited in cLaim 1, wherein the scanning station is provided with a lens system and said means includes a photocell located on the center of the respective circle.
 3. An identification station as recited in claim 1, wherein each code element includes a means for returning the light beam which falls on it originating in the light source.
 4. An identification system as recited in claim 1, wherein each code element is associated with a light-directing system which reverses the beam that falls on the code element and projects it along an axis passing through the center of the circle at a right angle to the plane thereof.
 5. An identification system as recited in claim 4, wherein each code element is mounted on a rotary element which is mounted on a flat face of the signal device for rotation about an axis passing through the center of the circle at a right angle to the face.
 6. An identification system as recited in claim 3, wherein the means for returning the light beam is a cable of optical fibers.
 7. An identification system as recited in claim 1, wherein the signal device moves with an article attached to a movable portion of a conveyor system, the scanning station is mounted on a fixed portion of the conveyor system, and the said means acts to switch the article when there is pattern identity between the code elements on the signal device and the light sources on the scanning station. 